1. Field of the Invention
The present invention relates to an evaluation system for evaluating vehicle condition of an engine-driven traveling vehicle. Such a system includes, for instance, a fuel consumption amount evaluation system for evaluating a fuel consumption amount by calculating a fuel consumption amount during traveling, a vehicle driving evaluation system for evaluating vehicle based on engine load, and so on.
2. Description of the Related Art
As apparatuses for calculating and displaying a fuel consumption amount, there are known an apparatus configured to obtain a fuel consumption amount through determination of the actual fuel flow rate with a flowmeter mounted in fuel piping, and an apparatus configured to obtain a fuel consumption amount through determination of the liquid level in the fuel tank. However, an apparatus for precision determination of the fuel flow rate in fuel piping is costly. Also, the calculation of short-term fuel consumption amount based on determination of an amount of fuel remaining in the fuel tank with reasonably high precision is difficult by itself.
On the other hand, in case the engine-driven traveling vehicle has an electronically controlled engine, such calculation of short-term fuel consumption amount is possible and feasible, based on a value of fuel injection amount exhibited by its common rail. The calculation is also possible and feasible in case the engine-driven traveling vehicle has an electronic governor controlled engine, based on detection of the position of its control rack. For example, a technique of precisely determining a fuel consumption amount based on a fuel injection amount by a fuel injection controller is known from JP 10-197314 A (see paragraph [0076] and FIG. 1). A fuel consumption amount indicating apparatus configured to calculate and display a fuel consumption amount based on detected position of the control rack is known from JP 2001-164981 A (see paragraphs [0007]-[0013] and FIG. 3). However, such calculation of fuel consumption amount is difficult with an engine-driven traveling vehicle having a mechanical governor controlled type engine, rather than an electronically driven engine or electronic governor controlled engine.
As an example of a vehicle driving evaluation system, JP 2006-076415 A (see paragraph [0006]-[0022] and FIG. 1) discloses a fuel saving driving (“eco-driving”) evaluation system configured to display or issue, only when needed, a real advice or a voice alarm relating to a speed changing operation. This fuel saving driving evaluation system includes an engine rotational speed sensor for determining an engine rotational speed of the vehicle, an accelerator opening degree sensor (e.g. a throttle position sensor), a vehicle speed sensor for determining a vehicle speed, a timer, a fuel meter for determining a fuel flow (delivery) rate, and an engine load sensor for determining an engine torque. Measured engine rotational speed, accelerator opening degree, vehicle speed, lapsed time, fuel flow (delivery) rate and engine load are stored as vehicle signals. Based on these vehicle signals, a vehicle mounted controller unit calculates a fuel consumption amount, an acceleration rate, a deceleration rate, and a travel distance of the vehicle. The vehicle mounted controller unit is configured also to display/issue a visual message or a voice message equivalent thereto which urges a shift-up operation (e.g. a message “a shift-up is recommended”) on the conditions that the engine rotational speed and the engine load are not less than predetermined values and the unit does not identify any climbing condition and that a message warning an excessive stepping-on of the accelerator pedal (e.g. a message “the accelerator is over-stepped) is not being displayed and the current speed of a multiple-step speed changer is at a speed lower than the highest speed thereof. Thereafter, when the engine rotational speed becomes below the predetermined value or the engine load becomes below the predetermined value or a judgment of a climbing condition is being issued, the controller unit stops the displaying of the message prompting a shift-up operation (the message “a shift-up is recommended”) and then returns the display to its normal screen.
Such driving evaluation system as above is capable of notifying the driver of various driving evaluations. However, the system requires a great number of sensors for obtaining many control parameters. In particular, the system would be costly if sufficient precision is to be obtained in the detection of the fuel flow rate by the fuel flowmeter or the detection of the engine load by the engine load sensor. Moreover, the system would result in a significant burden on both the hardware and the software, due to the large number of signals to be inputted to the controller unit.